Not a daft question Felters but one that will bring you many different answers and probably little in the way of conclusion.
For what it's worth I use any cheap 20/50 in the engine, but the important thing is to change it often,(1000 miles) this bit will get universal agreement.
Gear box I use a good 90, some opinions about some gear oils attacking bushes.
Forks - plenty fork oils available at bike shops, the weight is a personal thing, try one around 10 or 15 and make your own mind up as to how it rides, not that expensive that you can't experiment a bit.
Grease nipples on headstock (don't know why) brake cams (don't over-grease), clutch arm on gearbox